Oni Stones are the upgrade material that feeds your skills and the Oni Gauntlet in Onimusha: Way of the Sword, and there are 54 of them spread across Kyoto, Mount Oe, Arashiyama, and Shanoah Castle. They arrive four ways — plain treasure chests, mission and side quest rewards, Hidden Oni Treasure chests tied to Old Drawings, and Oni Portals. Collecting every last one in a single run still will not max out the Gauntlet.
Quick answer: Buy the three Oni Vision skills at a Spirit Mirror, then clear all 18 chest stones, every Chance Encounter and Mystery of Kyoto that pays out, Hidden Oni Treasure chests 1, 2, and 5, and the second and third Oni Portals — all before you accept the final mission, “The Clash At Rendaino.”
What Oni Stones are used for
Oni Stones and Power Stones are the two skill upgrade materials in the game, and both are required for the Well-Rounded trophy and achievement, which asks you to fully upgrade every skill. Power Stones are generous enough that one playthrough covers everything. Oni Stones are not.
Even with a perfect sweep, 54 stones is short of what the Gauntlet needs to be maxed. Your enhanced Skills and Oni Abilities carry into New Game Plus, so the intended route is to collect the stones again on a second run and finish the upgrades there.
Buy the Oni Vision skills before you hunt
Three Special Skills turn chest hunting from guesswork into a checklist: Oni Vision: Treasures, Oni Vision: Treasures 2, and Oni Vision: Search Range. All three are bought at the Spirit Mirror. Hold L2 and tap R2 to sweep the area, and nearby collectibles glow through walls and buildings.
Detected chests show up as Treasure markers on the area map, which is the fastest way to work a district without doubling back. Open the map, highlight a Treasure marker, and you can see exactly which corner of the current area still owes you something.
All Oni Stone chest locations
Eighteen Oni Stones sit in ordinary treasure chests. Most are anchored to a nearby Spirit Mirror, so fast travel to the mirror listed and walk out in the direction given. Two of these chests hold two stones each.
| Chest location | Stones |
|---|---|
| Kyoto — chest guarded by a Cleaver Genma | 1 |
| Kyoto Imperial Palace — chest in an alcove | 1 |
| West of the Gojo Street – East Spirit Mirror | 1 |
| Island in the west of Kyoto | 1 |
| Alleyway south of the Kiyomizu-dera Slope Spirit Mirror | 1 |
| Southeast of the Kiyomizu-dera Slope Spirit Mirror | 1 |
| Just north of Emma’s Hall | 1 |
| South of the Yasaka Shrine Spirit Mirror | 2 |
| Upstairs in a house east of the Shijo Street Spirit Mirror | 1 |
| West of the Shijo Street Spirit Mirror | 1 |
| North of the broken bridge in southwest Kyoto | 1 |
| Bamboo forest at the south of Kyoto | 1 |
| Mount Oe — Cave, past the second Genma blocking the Oni-kui Mushi Barrier | 1 |
| Mount Oe — first outcrop on the right heading up from the Castle Courtyard to the Cave | 1 |
| Arashiyama — east of the Temple Spirit Mirror | 1 |
| Shanoah Castle — same room as the Keep Area Spirit Mirror | 2 |
Pin a marker on the map before you set out. Selecting a Treasure marker brings up the Set Marker prompt, and the on-screen waypoint survives combat detours far better than memory does.
The Mount Oe chests are the easiest to walk past. Both sit off the main route through the Cave and the climb up from the Castle Courtyard, so sweep with Oni Vision at each junction rather than pushing straight for the next objective.
Oni Stones from missions and side quests
Twelve stones drop straight into your inventory as mission rewards. These land automatically as you push the story forward, so nothing here can be lost by playing normally.
| Mission or side quest | Stones |
|---|---|
| Careful What you Wish For | 1 |
| A Strength in Refuge | 1 |
| Patching up the Pouch | 1 |
| What Lurks in the Shadows | 1 |
| The Roots of All Evil | 2 |
| Shadows Fall | 1 |
| A Tempest at the Temple | 1 |
| Noisy Neighbors | 1 |
| The Demon on the Mount | 1 |
| In the Light of an Icy Moon | 2 |
Chance Encounters and Mysteries of Kyoto that pay Oni Stones
Optional NPC content accounts for the largest single block of stones — 16 in total. Most start by talking to a villager, an archer, or a merchant in Kyoto, Mount Oe, or Arashiyama.
| Name | Type | Stones |
|---|---|---|
| Pale Lights in a Night Sky | Chance Encounter | 1 |
| Ace Archer: Kiyomizu-dera Temple | Chance Encounter | 2 |
| Ace Archer: Mount Oe | Chance Encounter | 2 |
| Ace Archer: Arashiyama | Chance Encounter | 2 |
| The Odd Couples | Chance Encounter | 1 |
| A Fishy Story | Chance Encounter | 2 |
| Something in the Water | Mystery of Kyoto | 2 |
| The Faceless | Mystery of Kyoto | 2 |
| Worm-ly Ways | Mystery of Kyoto | 2 |
Note: “Something in the Water” only appears after you finish the “A Wife’s Prayer” Mystery of Kyoto. If it is missing from your tracker, that prerequisite is the reason.
Hidden Oni Treasure chests 1, 2, and 5
Three of the five Hidden Oni Treasure chests contain Oni Stones, two per chest, for six total. Each one begins when you pick up the matching Old Drawing, which sketches the hiding spot instead of marking it on the map.
Hidden Oni Treasure chests 3 and 4 exist too, but those hold Power Stones, not Oni Stones.
Oni Portals unlock in sequence
Two Oni Stones come from Oni Portals — one for clearing the second portal and one for the third. Portals are platforming challenges in the Oni realm, built around floating platforms and Oni Power to shift them into place, with a chest waiting at the end.
They are gated in order. A later portal will not open until you have finished the one before it, so if a portal refuses to activate, go back and clear the previous one first. Portal entrances show on the area map with their own marker.
The Point of No Return before “The Clash At Rendaino”
Nothing is permanently missable, but accepting the final mission, “The Clash At Rendaino,” shuts down free roam for good. The game shows a clear Point of No Return warning before it triggers.
Make a manual save at that warning. If you have already finished the story, choosing Continue from the main menu drops you back just before the finale with all progress intact, which lets you clean up any stone you skipped.
What carries into New Game Plus
Because the Gauntlet cannot be finished in one run, plan the second pass around what resets. Chance Encounters and Mysteries of Kyoto reset, which means their 16 stones are available again. Chest stones can be picked up again as well.
| Carries over | Resets |
|---|---|
| Oni Abilities and enhanced Skills | Mysteries of Kyoto |
| Hozuki Pouches and upgrades | Chance Encounters |
| Items, Charms and upgrades | Sword and Gauntlet enhancements |
| Genma Notes and Lion Dogs | Red Souls, Clothing, Spirit Mirror unlocks |
You will know the sweep worked when the skill upgrade screen at the Spirit Mirror stops blocking purchases for lack of Oni Stones, and the Well-Rounded trophy pops once every skill sits at maximum rank. If a stone still seems missing, the usual causes are a Chance Encounter you never spoke to, a Mystery of Kyoto still waiting on its prerequisite, or an Oni Portal you left unfinished, which locks the next one behind it.
